1. Field of the Invention
This invention relates to a multiroom air conditioner comprising plural outdoor side units each of which contains a compressor, an outdoor heat exchanger, etc., plural indoor side units each of which contains an indoor heat exchanger and an inter-unit pipe for connecting the plural outdoor side units and the plural indoor side units, which is capable of simultaneously cooling or heating all plural rooms, or simultaneously cooling some rooms and heating the other rooms through an individual control operation for each individual room.
2. Description of Related Art
There has been known a multiroom air conditioner in which plural outdoor side units each containing a compressor, an outdoor heat exchanger, etc. are connected to plural indoor side units each containing an indoor heat exchanger through an inter-unit pipe each comprising a high-pressure gas pipe, a low-pressure gas pipe and a liquid pipe to simultaneously cooling or heating rooms (as disclosed in U.S. Pat. No. 4,878,357).
In this type of multiroom air conditioner, the number of outdoor side units to be operated is adjusted in accordance with an indoor load. On the other hand, in a conventional air-conditional operation mode, when a stop signal is output from a controller to some outdoor side unit, a compressor, an outdoor heat exchanger, an outdoor fan and a refrigerant path change-over valve which are built in the outdoor side unit are simultaneously stopped every outdoor side unit. If this operation mode is applied to the multiroom air conditioner, it is not necessarily preferable for the multiroom air conditioner that all the equipments in the outdoor side unit are simultaneously stopped, and in some cases it is more preferable to control each of the equipments individually rather than the simultaneous control (stopping) operation.
Specifically, it has been hitherto adopted that the driving of a compressor and the operation of an outdoor heat exchanger are controlled simultaneously with each other. Therefore, it has been hitherto impossible to satisfy such a requirement that only the power (capacity) of the outdoor heat exchanger is increased during a driving time of the multiroom air conditioner to heighten the driving efficiency (output/input) of the air conditioner itself, and such a control device for meeting this requirement has not been proposed.